If you've ever been stuck at a sporting event or music festival with a clogged mobile network or snail's-pace Wi-Fi, salvation is at hand. FireChat, a new app for iOS, creates a hyper-local, anonymised chatroom using Apple's new Multipeer Connectivity Network -- using your iPhone's Bluetooth and Wi-Fi connectivity to directly connect to other iPhones in the immediate vicinity. One phone links to another, which links to another, to another, and pretty soon you've got a FireChat network going.

Multipeer Connectivity Network is a feature that was introduced as part of Apple's iOS 7 update, and Firechat is the first app we've heard of that uses MCN. Firechat is only for communicating between your phone and other devices running Firechat -- there's no provision for temporary Internet access, or any complex file sharing. It's simply a service to communicate with other Firechat users in your local area -- whether it turns out to be more useful for finding your friend in a crowded amphitheater, or for planning an impromptu hookup with some anonymous person on your train, only time will tell.

FireChat depends on a critical mass of devices running the app in any one location, which means you won't be able to use it unless at least one other person in range is as well. The practical maximum range of Bluetooth 4.0 is around 15 metres, although Wi-Fi is good for almost twice that under ideal circumstances -- so we're talking communication within a packed conference hall rather than an empty football stadium. At an absolute bare minimum, with the widest possible spacing to maximise coverage, you'd need about 120 people to provide FireChat connectivity to an area the size of the Sydney Cricket Ground's playing surface.

MCN is inaccessible to other platforms thanks to Apple's tight lockdown on its multi-factor authentication keys; this unfortunately means you won't see FireChat appearing on Android devices any time soon. It just might turn out to be the next must-have app for concertgoers and cricket attendees. [Firechat on the iTunes App Store]